Buggy code:
public class ItemRecommendation { static final String VERSION = "2.03" ; static IPosOnlyFeedback training_data ; static IPosOnlyFeedback test_data ; static List < Integer > test_users ; static List < Integer > candidate_items ; static SparseBooleanMatrix group_to_user ; static Collection < Integer > user_groups ; static CandidateItems eval_item_mode = CandidateItems . UNION ; static IRecommender recommender = null ; static IEntityMapping user_mapping = new EntityMapping ( ) ; static IEntityMapping item_mapping = new EntityMapping ( ) ; static SparseBooleanMatrix user_attributes ; static SparseBooleanMatrix item_attributes ; static String training_file ; static String test_file ; static ItemDataFileFormat file_format = ItemDataFileFormat . DEFAULT ; static String data_dir = "" ; static String test_users_file ; static String candidate_items_file ; static String user_attributes_file ; static String item_attributes_file ; static String user_relations_file ; static String item_relations_file ; static String save_model_file = null ; static String load_model_file = null ; static String user_groups_file ; static String prediction_file ; static boolean compute_fit ; static int cross_validation ; static boolean show_fold_results ; static double test_ratio ; static double rating_threshold = Double . NaN ; static int num_test_users ; static int predict_items_number = - 1 ; static boolean online_eval ; static boolean filtered_eval ; static boolean repeat_eval ; static String group_method ; static boolean overlap_items ; static boolean in_training_items ; static boolean in_test_items ; static boolean all_items ; static boolean user_prediction ; static int random_seed = - 1 ; static int find_iter = 0 ; static List < Double > training_time_stats = new ArrayList < Double > ( ) ; static List < Double > fit_time_stats = new ArrayList < Double > ( ) ; static List < Double > eval_time_stats = new ArrayList < Double > ( ) ; static void showVersion ( ) { } public static class ErrorHandler implements Recommender . ErrorHandler { public void reportError ( String message ) { } } static void usage ( String message ) { } static void usage ( int exit_code ) { } public static void main ( String [ ] args ) { } static void checkParameters ( ) { } static void loadData ( ) throws Exception { } static ItemRecommendationEvaluationResults computeFit ( ) throws Exception { } static ItemRecommendationEvaluationResults evaluate ( ) throws Exception { } static void predict ( String prediction_file , String predict_for_users_file , int iteration ) throws IOException { } static void predict ( String prediction_file , String predict_for_users_file ) throws IOException { } static void displayStats ( ) { if ( ( ItemRecommendation . training_time_stats . size ( ) ) > 0 ) { double max = Collections . max ( ItemRecommendation . training_time_stats ) ; double min = Collections . min ( ItemRecommendation . training_time_stats ) ; double avg = Utils . average ( ItemRecommendation . training_time_stats ) ; System . err . println ( ( ( ( ( ( "iteration_time:<seq2seq4repair_space>min=" + min ) + ",<seq2seq4repair_space>max=" ) + max ) + ",<seq2seq4repair_space>avg=" ) + avg ) ) ; } if ( ( ItemRecommendation . eval_time_stats . size ( ) ) > 0 ) { double max = Collections . max ( ItemRecommendation . eval_time_stats ) ; double min = Collections . min ( ItemRecommendation . eval_time_stats ) ; double avg = Utils . average ( ItemRecommendation . eval_time_stats ) ; System . err . println ( ( ( ( ( ( "eval_time:<seq2seq4repair_space>min=" + min ) + ",<seq2seq4repair_space>max=" ) + max ) + ",<seq2seq4repair_space>avg=" ) + avg ) ) ; } if ( ( ItemRecommendation . compute_fit ) && ( ( ItemRecommendation . fit_time_stats . size ( ) ) > 0 ) ) { double max = Collections . max ( ItemRecommendation . fit_time_stats ) ; double min = Collections . min ( ItemRecommendation . fit_time_stats ) ; double avg = Utils . average ( ItemRecommendation . fit_time_stats ) ; System . err . println ( ( ( ( ( ( "fit_time:<seq2seq4repair_space>min=" + min ) + ",<seq2seq4repair_space>max=" ) + max ) + ",<seq2seq4repair_space>avg=" ) + avg ) ) ; } <START_BUG> System . out . println ( ( "Memory:<seq2seq4repair_space>" + ( Memory . getUsage ( ) ) ) ) ; <END_BUG> } }

Fix:
System . out . println ( ( ( "Memory:<seq2seq4repair_space>" + ( Memory . getUsage ( ) ) ) + "<seq2seq4repair_space>MB" ) ) ;